SS*:一种嵌入视觉特性的多维图像索引算法

图像检索因信息量巨大，查询速度至关重要。一种有效的方法是对图像特征进行多维索引，然后按多维索引算法检索。但是，现有的多维索引算法并不是专门针对图像数据库设计的，没有考虑图像的视觉特性，检索性能不理想。文章针对图像信息的特点，结合SS多维索引算法，设计了一种新的基于内容的图像检索的多维索引算法——SS^*算法。实验表明，该算法对图像检索是有效的。     

一种支持快速相似检索的多维索引结构

由于科技信息技术的不断发展,传统的信息检索方式已经不能满足人们的要求,基于内容的图像检索属于一种支持快速相似检索的多维索引结构,应用于信息发达的网络世界。本文对基于内容的图像检索技术的工作流程进行分析,同时根据其特征探讨了常用的关键技术,对基于内容的图像检索技术的发展趋势作了进一步研究。     

基于嵌入式零树小波编码直方图图像检索

图像和视频应用的快速增长，使得根据图像和视频内容进行查询的技术变得越来越重要，人们提出了许多基于像素域或压缩域的图像检索技术，因为多媒体数据库通常具有相当大的数据量，所以基于像素域图像检索技术的计算复杂度相当大，因此，许多文献提出更快的基于压缩域的图像检索技术，本文提出一种改进的基于嵌入式零树小波编码直方图的图像检索技术，特征提取综合考虑图像的颜色，纹理，频率和空间信息，所有的特征可以在压缩过程中自动得到，图像检索的过程就是匹配待检索图像和来自数据库的侯选图像的索引，实验证明这种方法具有好的检索性能。     

基于内容的图像数据库检索技术分析

在互联网技术快速发展背景下,图像数据库建设不断完善,且被应用范围更为广泛,如数字图书馆、卫星图像数据库以及医学图像数据库等。而想要在海量数据中快速检索所需图像信息,就成了亟需解决的技术问题。基于内容来进行图像数据库检索为一种新型技术,主要是通过对图像视觉特征信息进行分析,如颜色、形状、纹理等来与数据库内信息进行对比,构建查询模块完成信息检索。本文对基于内容图像数据库检索技术进行了简要分析。     

基才高维局部特征和LSH索引的图像检索技术

基于内容的图像检索（CBIR）技术使从海量图像资源中快速高效地提取有价值的信息得以实现,采用局部特征来表示图像并在此基础上进行图像相似性检索是当前的热门研究课题。文中将图像高维局部不变特征提取算法和LSH索引算法应用到基于内容的图像检索系统中,实验结果表明了该方法的有效性。     

Hadoop分布式的海量图像检索

传统基于内容的图像检索方法通过相似度测量算法获取检索结果,对海量图像存在检索效率低和精度差的弊端,因此设计基于Hadoop分布式的海量图像检索方法,其基于Hadoop云平台对海量数码图像实施分布式运算,采集图像SURF特征,采用K-Means聚类方法将相似图像SURF特征聚集起来,通过TF-IDF数据挖掘技术对图像特征实施量化,进而基于Hadoop平台中的Lucene框架塑造海量图像数据的索引模块和搜索模块,依据用户输入的图像SURF特征塑造海量图像数据索引,完成相似图像的准确检索。实验结果说明,所提图像检索方法检索出的图像质量佳,对海量图像进行检索的效率和精度高。     

基于内容的图像检索技术

目前各行业对图像的使用越来越广泛,如何有效、快速地从大规模图像数据库中检索出需要的图像,是目前一个相当重要而又富有挑战性的研究课题.但传统的图像检索技术是基于文本的检索技术,这种方法虽然简单易行,但存在一些致命的缺点,严重影响了对图像信息的有效使用.为了克服传统方法的缺点,提出了基于内容的图像检索技术,该技术能够全面客观地提取图像内容,能有效地获取所需的视觉信息,能使图像数据库中的信息得到有效的管理.     

基于内容的图像检索技术

基于内容的图像数据库检索技术是当今的一个研究热点.本文介绍了基于内容图像检索的基本原理、检索方式和关键技术,并列举了几种较为先进的图像检索系统.最后探讨了当前研究中存在的问题以及今后的研究方向.     

基于SQL/MM的图像检索算法实现

对于大型图像数据库,如何实现高效的基于内容的图像检索成为图像数据库的主要研究方向之一.SQL/MM标准是一个基于内容来处理多媒体数据的数据库标准.利用SQL/MM标准中静态图像部分关于图像基本特征的SQL函数实现了基于内容的图像检索,并通过对Corel图像库的检索实验验证了标准中所涉及的各项特征的适用范围以及特性.     

图像场景相似性检测算法的研究

本文从图像内容的基础着手,结合当前的研究趋势,重点探讨了基于内容的图像检索(CBIR)方法。目前基于内容的图像检索技术大大的节省了人力,管理者也能从大量的、单调的人工管理工作中解放出来,并能够方便、快速、准确的从图像数据库中查找特定图像,是公安刑侦系统急需的技术之一。     

深度学习和迭代量化在图像检索中的应用研究

基于内容的图像检索的关键在于对图像进行特征提取和对特征进行多比特量化编码 。近年来,基于内容的图像检索使用低级可视化特征对图像进行描述,存在“语义鸿沟”问题;其次,传统量化编码使用随机生成的投影矩阵,该矩阵与特征数据无关,因此不能保证量化的精确度。针对目前存在的这些问题,本文结合深度学习思想与迭代量化思想,提出基于卷积神经网络VGG16和迭代量化(Iterative Quantization, ITQ)的图像检索方法。使用在公开数据集上预训练VGG16网络模型,提取基于深度学习的图像特征;使用ITQ方法对哈希哈函数进行训练,不断逼近特征与设定比特数的哈希码之间的量化误差最小值,实现量化误差的最小化;最后使用获得的哈希码进行图像检索。本文使用查全率、查准率和平均精度均值作为检索效果的评价指标,在Caltech256图像库上进行测试。实验结果表明,本文提出的算法在检索优于其他主流图像检索算法。      

Content-based retrieval of dynamic PET functional images

The recent information explosion has led to a massively increased demand for multimedia data storage in integrated database systems. Content-based retrieval is an important alternative and complement to traditional keyword-based searching for multimedia data and can greatly enhance information management. However, current content-based image retrieval techniques have some deficiencies when applied in the biomedical functional imaging domain. In this paper, we presented a prototype design for a content-based functional image retrieval database system for dynamic positron emission tomography (PET). The system supports efficient content-based retrieval based on physiological kinetic features and reduces image storage requirements. This design makes it possible to maintain a large number of patient data sets online and to rapidly retrieve dynamic functional image sequences for the interpretation and generation of physiological parametric images, and offers potential advantages in medical image data management and telemedicine, as well as providing possible opportunities in the statistical and comparative analysis of functional image data     

Effective image retrieval based on hidden concept discovery in image database.

This paper addresses content-based image retrieval in general, and in particular, focuses on developing a hidden semantic concept discovery methodology to address effective semantics-intensive image retrieval. In our approach, each image in the database is segmented into regions associated with homogenous color, texture, and shape features. By exploiting regional statistical information in each image and employing a vector quantization method, a uniform and sparse region-based representation is achieved. With this representation, a probabilistic model based on statistical-hidden-class assumptions of the image database is obtained, to which the expectation-maximization technique is applied to analyze semantic concepts hidden in the database. An elaborated retrieval algorithm is designed to support the probabilistic model. The semantic similarity is measured through integrating the posterior probabilities of the transformed query image, as well as a constructed negative example, to the discovered semantic concepts. The proposed approach has a solid statistical foundation; the experimental evaluations on a database of 10000 general-purposed images demonstrate its promise and effectiveness.     

Design and analysis of a content-based pathology image retrieval system

A prototype, content-based image retrieval system has been built employing a client/server architecture to access supercomputing power from the physician's desktop. The system retrieves images and their associated annotations from a networked microscopic pathology image database based on content similarity to user supplied query images. Similarity is evaluated based on four image feature types: color histogram, image texture, Fourier coefficients, and wavelet coefficients, using the vector dot product as a distance metric. Current retrieval accuracy varies across pathological categories depending on the number of available training samples and the effectiveness of the feature set. The distance measure of the search algorithm was validated by agglomerative cluster analysis in light of the medical domain knowledge. Results show a correlation between pathological significance and the image document distance value generated by the computer algorithm. This correlation agrees with observed visual similarity. This validation method has an advantage over traditional statistical evaluation methods when sample size is small and where domain knowledge is important. A multi-dimensional scaling analysis shows a low dimensionality nature of the embedded space for the current test set.     

基于内容的图像检索技术的研究与实现

如何为内容丰富多变的大量图像数据编制索引并利用该索引进行高效地相似检索是研究的核心问题。相似图像检索系统通过图像特征提取器提取图像的特征,提供访问图像内容的方法;距离函数是用来计算这些特征之间相似程度的主要工具。实验证明,该系统可以高效地为用户检索出指定特征的图像,对实际应用具有重要的价值。     

基于灰度和边界方向直方图的医学图像检索

本文研究了采用分级检索的机制,综合利用灰度及形状特征进行基于内容的医学图像检索的方法,该方法克服了灰度直方图不能充分表示空间分布信息的不足。利用边界方向直方图描述形状特征,避开了对图像进行精确分割这一医学图像处理中的难点问题。对CT图像数据库进行的检索实验,验证了该方法具有良好的检索性能。     

Feature selection for content-based image retrieval

In this article, we propose a novel system for feature selection, which is one of the key problems in content-based image indexing and retrieval as well as various other research fields such as pattern classification and genomic data analysis. The proposed system aims at enhancing semantic image retrieval results, decreasing retrieval process complexity, and improving the overall system usability for end-users of multimedia search engines. Three feature selection criteria and a decision method construct the feature selection system. Two novel feature selection criteria based on inner-cluster and intercluster relations are proposed in the article. A majority voting-based method is adapted for efficient selection of features and feature combinations. The performance of the proposed criteria is assessed over a large image database and a number of features, and is compared against competing techniques from the literature. Experiments show that the proposed feature selection system improves semantic performance results in image retrieval systems. This work was supported by the Academy of Finland, Project No. 213,462 (Finnish Centre of Excellence Program 2006–2011).